>> reporter: biden went right at ryan over mitt romney's controversial comments calling 47% of americans who don't pay income taxes irresponsible. >> the idea, if you heard that, that little soliloquy on 47%, you think he just made a mistake, then i got a bridge to sell you. >> i think the vice president very well knows sometimes the words don't come out of your mouth the right way. >> but i always say what i mean. >> reporter: when biden wasn't talking, he seemed oddly amused. by our count -- smiling or breaking out in laughter 92 separate times. expressive, often interrupting and occasionally personal. >> this is a bunch of stuff. look, here's the deal. >> what does that mean, a bunch of stuff? >> well, it means it's simply inaccurate. >> it's irish. >> it -- it is. we irish call it malarkey. >> thanks for the translation. >> reporter: and ryan needled ryan over the president's performance in last week's debate. >> i know you're under a lot of duress to make up for lost ground. but i think people would be better served if we don't keep interrupting each other. >> reporter: abc's martha